Analog Devices Inc. AD7091BCPZ-RL

Overview

AD7091BCPZ-RL from Analog Devices is a 12-bit successive approximation register (SAR) analog-to-digital converter optimized for ultralow-power, high-throughput data acquisition in space-constrained systems. It delivers 1 MSPS throughput at 3 V with 367 µA typical supply current, features an internal reference derived from VDD (0 V to VDD input range), and operates across −40°C to +125°C in an 8-lead 2 mm × 2 mm LFCSP package.

For engineers reviewing the AD7091BCPZ-RL datasheet, AD7091BCPZ-RL pinout, AD7091BCPZ-RL application, or AD7091BCPZ-RL equivalent, key selection considerations include its single-supply operation (2.09 V–5.25 V), SPI/QSPI/MICROWIRE-compatible serial interface, busy-indicator capability, flexible power/throughput scaling, and guaranteed no-missing-codes performance.

Technical Context

The AD7091BCPZ-RL implements a charge redistribution DAC architecture with integrated track-and-hold, enabling precise 12-bit conversion without external reference or clock. Its internal oscillator eliminates need for external timing components, while CONVST edge-triggered control synchronizes acquisition and conversion phases.

Power management is implemented via dual-mode operation: normal mode sustains full functionality for continuous 1 MSPS sampling, while power-down mode reduces supply current to 324 nA at 3 V between conversions-enabling dynamic power scaling aligned with system activity.

Key Specifications

Pinout & Package

AD7091BCPZ-RL is housed in an 8-lead, 2 mm × 2 mm lead frame chip scale package (LFCSP) with exposed pad (EPAD) for thermal and mechanical reliability. The EPAD must be soldered to GND for optimal thermal dissipation and solder joint integrity.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 12-bit SAR ADC applications.

Compared with ADS7042IRUGR and MAX11100ETE+, the AD7091BCPZ-RL offers lowest active current at 1 MSPS with zero external reference dependency-making it optimal for ultra-low-power, minimal-footprint, single-supply designs where reference simplicity and long battery life are critical.

Availability

AD7091BCPZ-RL is available at Aetrix Electronics and suitable for battery-powered handheld meters, medical point-of-care devices, and industrial motor monitoring systems requiring stable component supply across extended product lifecycles.

Supply support for AD7091BCPZ-RL includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Analog Devices, Inc. is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, headquartered in Norwood, MA.

The AD7091BCPZ-RL belongs to Analog Devices' ultralow-power precision SAR ADC product line, engineered specifically for energy-constrained, high-accuracy data acquisition in portable, medical, and industrial edge-sensing applications.

FAQ

What is the minimum supply voltage required for reliable operation of the AD7091BCPZ-RL?

The AD7091BCPZ-RL is specified to operate down to 2.09 V across the full −40°C to +125°C temperature range. Below this voltage, parameters such as INL, DNL, and SNR are not guaranteed. At 2.09 V, typical supply current remains 367 µA at 1 MSPS, enabling compatibility with partially discharged lithium primary cells or low-dropout regulators in brownout conditions.

Does the AD7091BCPZ-RL require an external reference voltage?

No, the AD7091BCPZ-RL does not require an external reference. Its reference is derived directly from the VDD supply, establishing an analog input range of 0 V to VDD. This eliminates external reference components, reduces BOM cost and PCB area, and avoids reference-related noise coupling-though VDD must be well-decoupled (10 µF + 0.1 µF) to maintain specified SNR and INL performance.

How does the power-down mode of the AD7091BCPZ-RL function, and what is its wake-up time?

The AD7091BCPZ-RL enters power-down mode when CONVST is held low prior to end-of-conversion (EOC). In this state, analog circuitry is disabled while the serial interface remains active, drawing only 324 nA at 3 V. Wake-up is initiated by a rising edge on CONVST, with a guaranteed 100 µs power-up time before the next conversion can begin-enabling rapid response in event-driven sensing architectures.

Can the AD7091BCPZ-RL interface directly with a 3.3 V microcontroller SPI bus?

Yes, the AD7091BCPZ-RL supports 3.3 V operation and is fully SPI-compatible. Its digital inputs accept 0.7 × VDD high and 0.3 × VDD low thresholds, and outputs drive VDD − 0.2 V high and 0.4 V low at 200 µA load-ensuring robust logic-level compatibility with standard 3.3 V MCUs. No level shifters are needed when VDD = 3.3 V.

What is the purpose of the REGCAP pin on the AD7091BCPZ-RL, and how must it be decoupled?

The REGCAP pin supplies the output of an internal low-dropout (LDO) regulator that powers the ADC core. It must be decoupled to GND with a 1 µF ceramic capacitor to stabilize the internal 1.8 V rail, suppress switching noise, and ensure accurate reference generation. Omitting this capacitor degrades SNR by up to 6 dB and increases INL error beyond ±1 LSB specification.